Refrigerating machine



Feb. 24, 1942.` 1 w. ATcHlsoN REFRIGERATING MACHINE Filed April 24, 1940 Inventor` Leonard W Atchison,

His Attorney.

Patented Feb. 24, 1942 REFRIGEBATING `MACHINE Leonard w. Atchison, Schenectady, N. Y., as'- signor to General Electric Company, a corporation of New York Application April 24, 1940, Serial No. 331,432

3 Claims.

This invention relates to refrigerating machines and more particularly to refrigerating machines of the primary-secondary type.

It is an object of my invention to provide a refrigerating machine of the primary-secondary type having an improved arrangement for the exchange of heat between the primary and secondary systems.

Further yobjects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing, in which Fig. l is a fragmentary perspective view of a domestic refrigerator embodying the particulars of my invention, and Fig. 2 is a side elevational, sectional view of the refrigeratorv shown in Fig. 1.

In accordance with my invention I have provided a refrigeratorll) having a primary system including an evaporator Il and a conduit I2 for conveying refrigerant from a suitable ow controlling means, such as a float chamber I3, or a capillary tube, to the evaporator or cooling element II .according to load requirements. Any

y suitable control may beemployed. I have also provided a secondary refrigerant system comprising a cooling portion I4 and a condensing portion I5. 'I'he condensing portion I5 and a section I6 of the conduit I2, which may be enlarged, if desired, as shown, are disposed in heat exchange relationship. In order to provide a neat appearance, the secondary system and the heat exchange portion of the primary system are preferably located in the insulation space between the outer case I'l and the inner liner I8 of the cabinet. The arrangement briefly described 'above is advantageous in that the transfer of heat between the secondary system and the section I6 of the primary system immediately preceding the entry of the refrigerant to the evaporator II increases the amount of vaporized refrigerant supplied to the evaporator and accordingly provides a greater injector capacity for the primary system. In addition, since refrigerant is furnished through theilow controlling means to the evaporator II only according to load requirements, the secondary system functions proportionally to the load because heat is exchanged only when the refrigerator load requires cooling by the primary evaporator.

Describing my invention in greater detail, I

have provided a refrigerator including a thermal-ly insulated cabinet I0 having a compartment I9 for the storage of food. An access opening 20 in the front wall thereof is arranged to be closed by a thermally insulated door 2l suitably hinged to the front vof the cabinet I0. The side and bottom walls of the cabinet comprise an outer case I1 and an inner lining I8 with suitable thermal insulation 22 disposed therebetween in order to minimize heat transfer into the interior of the cabinet. The top wall of the cabinet comprises a top liner 23 and a cover 24 and substantially the entire space therebetween is filled with suitable insulating material 25.

The primary evaporator II is connected in the refrigerant circuit of a refrigerating machine in cluding a motor compressor unit arranged in the machinery compartment within the cabinet I0 below the compartment I9. Access to the machinery compartment may be had by removing a panel 26.. The motor compressor unit has been omitted from the drawing for purposes of clarity. Refrigerant is supplied to the evaporator I I through a liquid line 21 and a flow controlling means, such as a float chamber I3 and a conduit I2. Vaporized refrigerant is returned to the motor compressor unit through a suction line 28, a portion of which is shown in Fig. l. During the operation of the primary system, the air in the upper portion of the compartment I9 is cooled by the cooling element or evaporator II and circulated downwardly, the warm air in the lower portion of the cabinet rising to take its place and the circulating air absorbing heat from the articles within the cabinet.

In a household refrigerator, it is frequently desirable to place closed containers therein for maintaining a relatively high humidity in order to prevent the dehydration of certain foods, such as vegetables. Frequently such receptacles are placed adjacent the bottom wall of the food storage compartment. As shown in the drawing, I have provided a frame 29 suitably supported from the walls of the compartment I9, the frame being provided with flanges or trackways for slidably supporting food storage receptacles 30. The frame 28 is arranged to support covers 3| for the receptacles. In the drawing I have illustrated the use-of glass cover members in order to permit the user of the refrigerator to inspect the interior of the receptacles without withdrawing the same. The frame ,29 is preferably spaced from the liner I8, as by supporting brackets 32, in order to permit circulation about the receptacles 30. It will be obvious, however, that only therefore less cooling capacity available to absorb` heat entering the food compartment through the bottom wall thereof. It is therefore desirable to provide some arrangement for lowering the temperature of the lower portion of the liner I8.

I have found that the additional cooling required may be obtained effectively by providing a container partially filled with a liquid vaporizable at the temperatures prevailing in the lower portion of the compartment I9 and including a liquid vaporizing portion I4 secured in good heat exchange relation with the bottom wall of the liner I3, and a second portion for condensing the vapor arranged in good heat exchange with the primary system. While I have shown a particular disposition of the cooling portion, it will be understood that the cooling portion of the secondary system may be disposed wherever supplemental cooling is desired.

In the embodiment illustrated, I provide a closed conduit 33 vwhich may be secured in good heat exchange relation with the liner I8, as by soldering, for example. The conduit is provided with a plurality of turns to form a cooling portion Il secured to the bottom wall of the liner I8. 'I'he container or conduit 33 is partially filled with a vaporizable liquid refrigerant, not shown, so that the turns of the portion Il are maintained flooded therewith. During the operation of the refrigerating machine, liquid in the cooling portion will be vaporized and the vapor will rise through the upright portions of the conduit 33 and circulate through the condensing portion I5 where it will be cooled by the heat exchange with the section I6 of the primary system and will be liquefied, the liquid returning to the lower portion of the conduit. Thus heat is carried away from the vapor passing from the lower portion of the conduit and the cooled liquid returning tends to supplement the cooling of the lower portion of the liner. As thus a,274,so4

sumciently large amount of liquid refrigerant to provide a cooling effect throughout the off described the condensation of refrigerant takes place in the condensing portion I5 of the secondary system only when the portion i6 of the primary system contains refrigerant. Normally,

this means that refrigeration is had in the secondary system only when liquid refrigerant is being supplied from the float chamber I3 to the primary evaporator II, and the refrigerating cycle of the secondary evaporator I4 is substantially the same as that of the primary evaporator II. In other words, the secondary system supplements the primary system. It should be noted, however, that when the float mechanism in the float chamber I3 closes the passage I2 to the primary evaporator, liquid refrigerant will remain in the loop portion immediately below the float chamber and liquid refrigerant will be trapped in the enlarged portion I6 of the primary system. These sources of liquid refrigerant will continue to exert a cooling effect on the condensing portion I5 of the secondary system for a substantial interval of time following the shutdown of the compressor utilized to circulate refrigerant in the primary system. Moreover, the enlarged portion I6 of the primary system traps a certain amount of liquid refrigerant which period of the refrigerant circulating means.

In order to maintain the portions I5 and I6 of the secondary and primary systems. respectively, in good heat exchange relationship, I have provided spring clips 34. To further facilitate goodheat transfer between primary and secondary, a material of high thermal conductivity such as a plastic material having particles of a heat conductive material dispersed throughout may be applied to the portions I5 and I8.

In assembling a cabinet'embodylng my invention, I rst arrange the outer casing I1 and the inner lining I3 in their proper places with the insulating material 22 therebetween and the conduit 33 secured to the outside of the lining I3. The refrigeratlng machine is assembled separately, the evaporator Il being suitably secured to the top liner 23. The evaporator is then lowered through the upper end of the cabinet and the top liner 23 suitably secured to the inner lining I8. 'I'he portions I5 and I6 are then suitably joined togetherl in intimate thermal association as by applying the spring clips 33, following which any thermally conductive material is applied and loose insulation 35 is packed around the upper end of conduit 33 and the float chamber I3. The cover 24 is then applied, the inturned flange 36 of the cover engaging a spring clip 31 and the rear end of the cover being suitably secured to the outer liner I1 as by means of a member 33 suitably secured to the cover and the outer case.

While I have illustrated the heat exchange portions of the primary and secondary systems in the insulation space between the walls of the cabinet, it will be understood that the heat exchange may take place at any point between t'he flow controlling means I3 and the evaporator While I have described an embodiment of my invention in connection with a household refrigerator, other applications will readily be apparent to those skilled in the art. I do not, therefore, desire my 'inventionto be limited to the particular construction shown and described and I intend in the accompanying claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A refrigerator comprising a cabinet having a food storage compartment, a primary refrigerating system including a cooling element located in one region of said compartment, a secondary refrigerating system comprising a cooling portion constructed and arranged for cooling another region of said compartment and a condensing portion, means for conducting refrigerant to said cooling element, said condensing portion and said conducting means being arranged in heat exchange relationship.

2. A refrigerator comprising a cabinet including inner and outer walls having an insulation space therebetween and dening a food storage compartment, a primary refrigerating system including a cooling element located in one region of said compartment, a secondary refrigerating system comprising a cooling portion constructed and arranged' for cooling another region of said compartment and a condensing portion, means for conducting refrigerant to said cooling element, said condensing portion and said conductlarged portion I6 suniciently large to trap a 75 ing means being arranged in heat exchange resecondary refrigerating system comprising a cooling portion constructed and arranged for cooling another region of said compartment and a condensing portion, said condensing portion and the portion of said conduit between said element and said flow controlling means being arranged in heat; exchange relationship.

LEONARD W. ATCHISON. 

